CD274 and esophageal squamous cell carcinoma: For the 6 trials (CheckMate-648,1 ESCORT,6 KEYNOTE-181,5 KEYNOTE-590,3 ORIENT-15,4 and ORIENT-29) that reported HRs but not KM curves for the subgroup of patients with ESCC with low PD-L1 expression, time-to-event outcomes were derived with KMSubtraction.